Re: [boost] ARM thumb support in spinlock_gcc_arm.hpp

Subject: Re: [boost] ARM thumb support in spinlock_gcc_arm.hpp
From: Peter Dimov (pdimov_at_[hidden])
Date: 2008-09-05 18:27:51

Jerry Napoli:

> Hi,
>
> I'm trying to compile using boost 1_36_0 for ARMv6 Thumb for iPhone 
> development.  The compiler used is gcc 4.0.x supplied with the iphone sdk.
>
> I run into issues with the inline assembly inside 
> boost/detail/spinlock_gcc_arm.hpp.  It generates a SWP instruction which 
> (AFAIK) is not supported in thumb mode.  The gnu arm assembler gives me a 
> 'bad instruction ...' error.  I'm able to work around it by modifying 
> spinlock.hpp to include spinlock_sp.hpp instead.

I assume you mean spinlock_nt.hpp?

Unless someone comes up with a better solution, we probably need to replace

#if defined(__GNUC__) && defined( __arm__ )
#  include <boost/detail/spinlock_gcc_arm.hpp>
#elif defined(__GNUC__) && ( __GNUC__ * 100 + __GNUC_MINOR__ >= 401 )
#  include <boost/detail/spinlock_sync.hpp>

with

#if defined(__GNUC__) && defined( __arm__ ) && !defined( __thumb__ )
#  include <boost/detail/spinlock_gcc_arm.hpp>
#elif defined(__GNUC__) && ( __GNUC__ * 100 + __GNUC_MINOR__ >= 401 ) && 
!defined( __arm__ )
#  include <boost/detail/spinlock_sync.hpp>

Does this change help?